Efficient, fast and cost-effective techniques are still required for analyses of single nucleotide polymorphisms (SNPs) and known mutations associated with disease. Many methods have been developed for SNP/mutation genotyping (Landergren et al. 1998). The DNA-chip method based on hybridization may allow processing large numbers of samples, but it requires careful calibration of the signal when interpreting data (Wang et al. 1998). Single base extension (SBE) followed by separation with capillary electrophoresis using automated sequencing instrument is limited by the length of the extension primer that can be synthesized by present technology. For instance, no more than 10 SBE products are separated in a single capillary using the Applied Biosystems' SNaPshot kit (from Protocol of ABI Prism SNaPshot Multiplex Kit, 2000). Detection of SBE reactions by mass spectrometry requires highly purified products, which can be costly and labor-intensive (Ross et al. 1998). For a more thorough review of the field, please see a number of papers published in a supplement to BioTechniques, June 2002, under the title—SNPs: Discovery of markers for disease.